Oneday I imagined a similar 'electric power supporter unit' for A-bike.
There were two problems.
1. Avoiding the interference between pedals and the unit.
2. An 'additional freewheel mechanism' on the unit.

He seems to solve the first problem clearly !!
Good technician, he is..

Everything works well, much less stress on the frame through lack of pedalling, speed is about 15+mph due to gearing but I havent tested battery life yet, I guess it's as long as how large a battery you fancy carrying in your back pack.

I guess all the RC hobby folks could give you advice on batteries
and how to get the most out of them.

Are you able to pedal it together with the motor when you go uphill?

If you switch off the motor and pedal does the motor turn and
make it more heavy to turn the cranks ?

what effect on the motor and what was it used for, intended for?

The little black box is that a motor relay? I have "built" radios but not
motors so I know nothing about such.

The good thing with such an arrangement you have is that the battery
is so flexible. You could change it very easy between litium to metal hybrid
or lead depending of what is sold locally at bargain price.

The little black box is indeed a 24V 80A relay which is the "controller". I decided to go for a simple on/off switch for the motor rather than a scooter style throttle grip and speed controller combination (although I do have these in my spares box). 80A is probably overkill because the whole circuit is protected by a 35A fuse inside the seat but it was what I had lying around and it fitted fine. You could fit a 40A version from here : http://www.technobots.co.uk/acatalog/Online_Catalogue_Relays_360.html

I can pedel (or freewheel) whether the motor is engaged or not but there is a little extra friction of the motor and drive chain to overcome. It is benefitial for battery life to start cycling as normal and then once started, switch on the motor (push button switch) for an easy ride. Release the push button to switch the motor off and brake as normal.

The batterys I use are 2x12V 7.5Ah SLA wired in series to give 24V carried in a backpack. These are a cheaper at £12 each but a heavier solution than a Lithium Ion alternative which comes in at £200 from here : http://www.poweredbicycles.co.uk/MOTOPB7/513.htm

The motor is a general purpose scooter motor 24V - 250W - 13.5A - 2750RPM which I bought from ebay although they are available elsewhere.